Method for installing electrodes



Dec. 18, 1962 R. C. HERGENROTHER ETAL METHOD FOR INSTALLING ELECTRODESFiled 001;. 28, 1959 mvsmons RUDOLF c. HERGENROTHER ALVIN s. LUFTMANCARLETON E. SAWYER DANIEL D. DUGGAN M/MM ATTORNEY United States Patent3,068,548 METHGD FOR INSTALLING ELECTRODES Rudolf C. Hergenrother, WestNewton, Alvin S. Luftman, Natick, Carleton E. Sawyer, Acton, and DanielD. Duggan, Watertown, Mass, assignors to Raytheon Company, Lexington,Mass, a corporation of Delaware Filed Oct. 28, 1959, Ser. No. 849,286 8Claims. (Cl. 2925.16)

This invention relates to methods for installing electrode structures ina bulb and, more particularly, to a method of installation wherebyelectrodes are properly aligned with each other and with the bulb andare perpendicular to the bulb axis. The invention is suitable, forexample, for installing the storage, collector and screen grids in theone-gun storage tube described in US. Patent 2,661,442 to I. A. Buckbeeor the storage, decelerating and accelerating electrodes in the one-gunstorage tube described in application #517,830 of R. C. Hergenrother nowPatent No. 2,922,071 issued January 19, 1960, or the screens in atwo-gun storage tube such as described in the January-February 1959issue of Electronic Progress published by Raytbeon Company, Waltham,Massachusetts.

In the past such electrodes or screens have been installed or mounted ina glass bulb by first annealing small metal buttons or Valkert Stampingsto the walls of the glass bulb at positions located externally from thebulb, then, after aquadaging the bulb, inserting each electrodeseparately and Welding each to conductive support pins which are passedthrough thebuttons. This prior method has resulted in unsatisfactoryorientation of the electrodes relative to each other and impropercentering of the electrodes on the bulb axis with the result that theaxes of the electrodes are not collimated with beams from electron gunslocated axially in the bulb and uniformity of production is less thandesired. These unsatisfactory results are primarily attributed to theimproper location of the buttons and distortion of the electrodes asthey are individually and separately welded inside the bulb to thesupport pins. Furthermore, even when the buttons are properly located itis difiicult to center each electrode on the bulb axis and tosubsequently weld it in place. There fore, it is an object of thepresent invention to provide a method for installing electrodes in abulb whereby certain unsatisfactory results or prior methods, mentionedabove, are avoided.

It is another object to provide a method for installing a plurality ofelectrodes in a bulb whereby proper orientation of electrodes withrespect to each other is insured.

It is another object to provide such a method whereby said buttons areprecisely fixed to the bulb and properly orientated electrodes are fixedto saidbuttons producing an electrode structure in a bulb disposedperpendicular to the axis of said bulb.

It is a feature of the present invention to install a plurality ofelectrodes in aglass bulb by first inserting an alignment jig into saidbulb coaxial therewith, said jig being indexed adjacent to said bulb,fastening buttons to said bulb at said index points, removing said jig,inserting said electrodes into said bulb, inserting support pins throughsaid buttons and into suitable alignment holes or depressions in saidelectrodes and welding said support pins to said buttons. i

It is another feature to drill alignmentholes in a plurality ofelectrodes and then assemble the electrodes forming a rigid structurebefore insertion into the bulb.

It is another teature to drill the alignment holes in each of theelectrodes and then to assemble the electrodes with said alignment holesorientated in a predetermined manner and to locate said indexes on saidjig in an identical manner so that buttons aligned with said indexeswill also be aligned with said alignment holes.

Other objects and features of the present invention will be moreapparent from the following specific description taken in conjunctionwith the drawings in which:

FIG. 1 is a pictorial view showing the jig inserted in the bulb andbuttons aligned with index holes in said jig;

FIG. 2 depicts a button with an index pin through its center; 1

FIG. 3 shows a plurality of electrodes such as employed in a typicalstorage tube;

FIG. 4 shows an assembly of said electrodes;

FIG. 5 is. an enlarged view of one end of said jig showing the relativeorientation of index holes; and

FIG. 6 shows the electrode assembly installed in said bulb and supportedby support pins which are welded to the buttons.

Turning first to FIG. 1 there is shown what is substantially the firststep in the assembly of an electrode structure in a glass bulb. Theglass bulb 1 is preferably of the type employed for constructing storagetubes and has an elongated neck of constant diameter at one end and isopen at the other end. A jig 2 with padding rings 3 and 4 attached tothe cylindrical portion thereof is inserted into the glass bulb. Thecylindrical portion of the jig is somewhat smaller than the insidediameter of the bulb neck, but fits snugly therein and is spaced fromthe bulb neck by rings 3 and 4.

The neck end of the bulb butts against a plate 5 to which the jig isattached and thereby establishes the longitudinal position of the jigrelative to the glass bulb. This plate 5 is fixed to the end of the jig2 after the jig is inserted in the glass bulb.

At the other end of the jig there are a numberof protuberances whichmight, for example, extend from the jig in an axial manner as shown.Index holes such as 7 and 8 are drilled at predetermined points on theseprotuberances and directly axially with the bulb and the jig. Thelocation of these index holes will be described later with reference toFIGS. 3, 4 and 5.

Next, metallic buttons such as 9 and 10 each having an index pin throughits center such as index pins Hand 12 are inserted into holes 13 and 14cut in glas's bulb 1 which are directly opposite index holes 7 and 8,respectively. The buttons 9 and 10 are inserted so that the index pinsfit into index holes 7 and 8, thereby securely supporting and aligningbuttons 9 and 10 with the holes; Once aligned and supported in thismanner, the buttons are annealed to the surface of the glass bulbforming a vacuum seal therewith.

Turning next to FIG. 3 there are shown three rin'g'electrodes whichmight, for example, be the screen 15, the storage 16 and the collector17 grids in storage tubes such as described in the first mentionedreference. Perpendicular holes 18, 19 and 20 aredrilled in each of theelec-, trodes as shown in FIG. 3 and are spaced identically in eachelectrode. Any number of such holes may be drilled, but for purposes ofexample only three such. are shown in each electrode. Radial alignmentholes 21, 22

and 23 are also drilled in each of the electrodes at different points oneach so that when the electrodes are stacked one upon another and theholes denoted 18, 19 and 20 in each of the electrodes are all in line,the alignment holes 21, 22 and 23 will be disposed with respect to eachother in a predetermined manner. For example, these alignment holesmight be disposed at 120 radial degrees from each other.

The rings shown inVFIG. 3 are assembled as shown in FIG. 4. They arespaced from each other by ceramic spacers such as spacers 24 and 25 andfastened together pins 26, 27 and 28 inserted through the holes 18, 19and 20, respectively. Pins 26, 27 and 28 are preferably sheathed in aceramic material to prevent short circuiting the electrodes to eachother. Only two of the alignment 7 holes 21, 22 and 23, shown in FIG. 3,are shown in FIG. 4.

It should be noted that the alignment holes are drilled radially withrespect to the electrodes on lines perpendicular to the axis of theelectrodes. Consequently, upon assembly in the manner described above,the alignment holes will be displaced radially as Well as axially withrespect to each other, the radial displacement being 120 degrees apartand the axial displacement as represented by dimensions AB and BC inFIG. 4. The dimension AB is the axial displacement of alignment hole 23from alignment hole 22 and the dimension BC is the axial displacement ofthe hole 21 from the hole 22. These dimensions also determine theorientation of the index holes, such as 7 and 8, which are drilled inthe protuberances, on jig 2 as shown in FIG. 5. Index holes 7 and 8might, for example, match holes 22 and 23 in the storage and collectorelectrodes and are, consequently, located axially with respect to eachother on circumferential center lines 29 and 30 shown in FIG. 5, whilealignment hole 21 in the screen electrode is located on centerline 31 inan opposite protuberance.

When the buttons are annealed to the glass tube 1 their index pins, suchas pins 11 and 12, are removed. Next the base plate is removed from jig2 and the jig is removed from the bulb leaving the bulb with buttonsprecisely located and annealed in its surface forming air-tight sealstherewith. 7

: Next, the assembly of electrodes, shown in FIG. 4, is

' inserted in the large end of bulb 1 substantially coaxial with thebulb and support pins of the same diameter as the pins and machined atone end to fit into the alignment holes are inserted in each of thebuttons and into the alignment holes 21, 22 and 23 thereby supportingthe electrodes and providing electrical leads thereto.

In this manner the electrode assembly is precisely orientated andsupported inside the glass bulb 1 so that the electrodes are properlyspaced from each other and collimated with an electron gun which may beaxially disposed in the'nech of the bulb. In FIG. 6 there is shown aview of the electrode assembly installed and supported in this manner bysupport pins 32, 33 and 34 which fits snugly into alignment holes 22, 23and 21.

I The support pins are then externally welded to the buttons therebyadding rigidity to the installation and sealing the support pins and,subsequently, the external part of these support pins are cut oflleavingonly a suitable part' for attaching to electrical leads. V A

While there-is described above a method for installing an electrodestructure in a glass bulb so as to obtain proper spacing of electrodesand collimation with the 7 sunset the bulb, his. to be understood that adifierently What is claimed is:

l. A method for mounting electrodes in a bulb comprising the steps ofinserting an alignment jig into said bulb, said jig being indexed atpoints adjacent to said bulb, fastening support members to the surfaceof said bulb at said index points, removing said jig, inserting saidelectrodes into said bulb, inserting support pins through said supportmembers and into suitable depressions in said electrodes and fasteningsaid support pins to said support members.

2. A method for mounting electrodes in a bulb comprising the steps ofinserting an alignment jig into said bulb, said jig being indexed atpoints adjacent to said bulb, fastening metallic discs to the surface ofsaid bulb at said index points, removing said jig, inserting saidelectrodes into said bulb, inserting support pins through holes in saiddiscs and into suitable depressions in said electrodes and" fasteningsaid pins to said discs.

3. A method for mounting electrodes in a glass bulb comprising the stepsof inserting an alignment jig into said bulb, said jig being indexed atpoints adjacent to said bulb, cutting holes in the surface of said bulbopposite said indexes, inserting metallic discs in said holes oppositesaid index points, annealing said discs to the surface of said glassbulb, removing said jig, inserting said electrode into said bulb,inserting support pins through said metallic discs and into suitabledepressions in said electrodes and fastening said support pins to saiddiscs.

4. A method for mounting electrodes in a glass bulb comprising steps ofinserting an alignment jig into said bulb, said jig having radial indexholes at points adjacent to said bulb, cutting holes in said glass bulbopposite said index holes, fastening metallicbuttons to said glass bulbat locations axial with said index holes, removing said jig, insertingsaid electrodes into said bulb, inserting support pins through saidbuttons and into suitable depressions in said electrodes and weldingsaid support pins to said buttons.

5. A method for mounting electrodes in a bulb comprising the steps ofinserting an alignment jig into said bulb, said jig being coaxial withsaid bulb and indexed at radial points adjacent to said bulb, fasteningsupport discs to said bulb opposite said index points, removing saidjig, inserting said electrodes into said bulb, inserting support pinsthrough said discs and into suitable depressions in said eletcrodes andfastening said support pins to said discs,

6. A method for mounting electrodes in a bulb comprising the steps ofinserting an alignment jig into said bulb, said jig being coaxial withsaid bulb and indexed at points adjacent thereto, fastening supportmembers to said bulb opposite said index points, said support membershaving-index pins through their centers to insure that each of saidmembers'is aligned with an index point before fastening, removing saidindex pins, removing said jig, inserting said electrodes into said,bulbs, inserting support pins through the centers of said supportmembers and into suitable depressions in said electrodes and fasteningsaid support pins to said support members.

7. A method for mounting a plurality of electrodes in a glass bulbcomprising the steps of inserting an alignment jig into said bulb, saidjig being coaxial with saidbulb and indexed at points adjacent to theinside surface of said bulb, annealing metal buttons tothe surface ofsaid glass bulb opposite said index points, each of said buttons havingan index pin through its center for aligning said button with one ofsaid indexpoints, removing said index pins from said buttons, removingsaid jig from said glass bulb, inserting said electrodes into said glass.bulb, inserting electrically-conductive support pins through saidbuttons and into suitable depressions in said electrodes and weldingsaid support pins to said buttons.

8. method for mounting a plurality of electrodes in a glass bulbcompiising the steps of assembling sai electrodes, drilling alignmentholes in said electrodes, said assembled electrodes forming a rigidstructure with a predetermined orientation of said alignment holes,inserting an alignment jig into said bulb, said jig being coaxial withsaid bulb and having index holes drilling therein disposed with respectto each other in substantially the same manner as said alignment holesare disposed in said electrode structure, annealing metal buttons tosaid glass bulb, each of said buttons having an index pi: through itscenter for aligning said button with a different 5 port pins to saidbuttons.

References in the file of this patent UNITED STATES PATENTS Hughes Feb.7, 1956 2,876,376 Rienks Mar. 3, 1959

